00:01
We first need to check that these three polynomials form an orthogonal basis.
00:06
So let's write the vectors p0 bar, p1 bar and p2 bar given by evaluating the respective polynomial in the points minus 5, minus 3, minus 1, 1, 3 and 5.
00:17
So of course, p0 bar is just all ones.
00:20
P1 bar is exactly those points.
00:23
And p2 was given so that this vector p2 bar has small integers.
00:32
In fact, it turns out to be exactly 5, minus 1, minus 4, minus 1, 5.
00:38
Now we need to check that these three polynomials are orthogonal with respect to this particular product.
00:44
So p0 against p1, this by definition is p0 bar dot p1 bar.
00:52
And if you do this dot product between vectors in r6, you see merely that this is a 0.
01:00
So p0 and p1 are orthogonal.
01:03
Then similarly p0 against p2, again is p0 bar...